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This presentation proposes an approach to use ABS wheel speed sensor signals together with other vehicle state information from a brake control module to detect an unbalanced tire or tires in real-time. The proposed approach consists of two-stage algorithms that mix a qualitative method using band-pass filtering with a quantitative parameter identification using conditional least squares. This two-stage approach can improve the robustness of tire imbalance or imbalances. The proposed approach is verified through vehicle testing and the test results show the effectiveness of the approach. Presenter Jianbo Lu, Ford Motor Co.

Incremental Sheet Forming (ISF) is an emerging sheet metal prototyping technology where a part is formed as one or more stylus tools are moving in a pre-determined path and deforming the sheet metal locally while the sheet blank is clamped along its periphery. A deformation analysis of incremental forming process is presented in this paper. The analysis includes the development of an analytical model for strain distributions based on part geometry and tool paths; and numerical simulations of the forming process with LS-DYNA. A skew cone is constructed and used as an example for the study. Analytical and numerical results are compared, and excellent correlations are found. It is demonstrated that the analytical model developed in this paper is reliable and efficient in the prediction of strain distributions for incremental forming process.

This paper presents the extended Kalman filter-based sideslip angle estimator design using a nonlinear 5DoF single-track vehicle dynamics model with stochastic modeling of tire forces. Lumped front and rear tire forces have been modeled as first-order random walk state variables. The proposed estimator is primarily designed for vehicle sideslip angle estimation; however it can also be used for estimation of tire forces and cornering stiffness. This estimator design does not rely on linearization of the tire force characteristics, it is robust against the variations of the tire parameters, and does not require the information on coefficient of friction. The estimator performance has been first analyzed by means of computer simulations using the 10DoF two-track vehicle dynamics model and underlying magic formula tire model, and then experimentally validated by using data sets recorded on a test vehicle.

This paper proposes an approach that characterizes a driver's driving behavior and style in real-time during car-following drives. It uses an online learning of the evolving Takagi-Sugeno fuzzy model combined with the Markov model. The inputs fed into the proposed algorithm are from the measured signals of on-board sensors equipped with current vehicles, including the relative distance sensors for Adaptive Cruise Control feature and the accelerometer for Electronic Stability Control feature. The approach is verified using data collected using a test vehicle from several car-following test trips. The effectiveness of the proposed approach has been shown in the paper.

The ISO TC22/SWG2 - Brake Lining Committee established a task force to determine and analyze root causes for variability during dynamometer brake performance testing. SAE paper 2010-01-1697 “Brake Dynamometer Test Variability - Analysis of Root Causes” [1] presents the findings from the phases 1 and 2 of the “Test Variability Project.” The task force was created to address the issue of test variability and to establish possible ways to improve test-to-test and lab-to-lab correlation. This paper presents the findings from phase 3 of this effort-description of factors influencing test variability based on DOE study. This phase concentrated on both qualitative and quantitative description of the factors influencing friction coefficient measurements during dynamometer testing.

This paper proposes an approach to use ABS wheel speed sensor signals together with other vehicle state information from a brake control module to detect an unbalanced tire or tires in real-time. The proposed approach consists of two-stage algorithms that mix a qualitative method using band-pass filtering with a quantitative parameter identification using conditional least squares. This two-stage approach can improve the robustness of tire imbalance or imbalances. The proposed approach is verified through vehicle testing and the test results show the effectiveness of the approach.

Sampling-based methods are general but time consuming for solving a Reliability-Based Design Optimization (RBDO) problem. In order to alleviate the computation burden, score function together with the Monte Carlo method was used to compute the stochastic sensitivities of reliability functions. In literature, re-weighting schemes were shown to converge faster than the regular Monte Carlo method. In this paper, a reweighting scheme together with score function is employed to perform sampling-based stochastic sensitivity analysis to improve the computational efficiency and accuracy. An analytical example is used to show the advantages of the proposed method. Comparisons to the conventional methods are made and discussed. Two RBDO problems are solved to demonstrate the use of the proposed method.

The Reverse Braking Assist (RBA) feature is designed to automatically activate full braking in a backing vehicle. When this feature activates, a backing vehicle is suddenly stopped or may slide to a stop. During this process, an understanding of the driver's behavior may be useful in the design of an appropriate human-machine-interface (HMI) for the RBA. Several experimental studies were done to examine driver behavior in response to an unexpected and automatic braking event while backing [1]. Two of these studies are reported in this paper. A 7-passenger Crossover Utility Vehicle was fitted with a rear-view camera, a center-stack mounted LCD screen, and ancillary recording devices. In the first study, an object was suddenly placed in the path of a backing vehicle. The backing vehicle came to a sudden and complete stop. The visual image of the backing path on the LCD prominently showed that an obstacle was present in the backing path of the vehicle.

Each more the consumer uses the vehicle noise, vibration, and harshness (NVH) attributes to define the vehicle model when purchasing a car, so the sound quality development is very important to guarantee the automaker success in a competitive market. Several vehicle components contribute to the consumer sound quality perception, as engine, gearbox and exhaust systems. So those components improvement is necessary in order to enrich the sound perception. In this article will be developed a case study that evaluates the contribution and the characteristics of the irradiated noise from the power steering system, which was classified as moan, whine and hiss noise, defines objectively each phenomena and evaluate the proposed systems.

Improvement of engine fuel efficiency through the use of low friction engine oils is a major task in engine lubrication research. This friction reduction can be achieved by improving the rheological characteristics and elastohydrodynamic (EHD) properties of engine oils, and by controlling boundary chemical interactions between oil-based additives and lubricated components in the engine. In order to achieve minimal frictional power loss under all lubrication regimes, engine tribological systems must be designed to effectively use advanced lubricant technology, material and surface modifications. This paper presents results of cooperative research addressing opportunities for minimizing friction through extension of hydrodynamic lubrication regime in lubricated components using various formulation approaches. A set of experimental oils has been evaluated using laboratory test rigs that simulate hydrodynamic, EHD, mixed and boundary lubrication.

Current road vehicles have tendency of use softer suspension springs to improve ride comfort, but as a moving device with suspension system, vehicles have other parts that can affect attributes for comfort perception, and is necessary the correct definition of which one should be modified to address the comfort issue and avoid impact in attributes for stability. Usually springs are not the main responsible for bad comfort behavior, but shock absorbers and bushings are. A typical passenger car shows a wide possibility of loads carriage and how to set up correctly the suspensions considering its tradeoffs and brand DNA is the main issue.

This work presents a statistical approach for simulation based on Monte Carlo method. As an exercise of the method a CAE vehicle dynamics model was specifically created to evaluate the likelihood to meet a given target driving a maneuver for given inputs variations. In the exercise, three different inputs were chosen as stochastic inputs (also called noise factors) and all relevant information about their statistics has been raised, based in components information. The chosen inputs are: front/rear dampers curves, front/rear ride heights and tire surface temperature. A brief description of the Monte Carlo technique is presented. The choice of this method is due to the reduced number of simulations required to have a given accuracy in comparison with other approaches, especially for multivariable system. As output variable for the exercise, the tire patch height was chosen and the resulting probability density function of it is presented.

In South America and other emerging markets sound package development is limited by the cost and weight of its components. Reaching the right balance between cost and a good NVH performance provides an important competitive advantage, therefore any achieved design opportunities can be replicated to other vehicle lines and markets. In this work the main noise transmission paths are verified by evaluating the contribution of sound package components to noise attenuation in two cases, initially from the tire contact patch through vehicle body to a number of positions within the vehicle interior and, next, from the engine compartment, by placing a High Frequency Sound Source (HFSS) at engine faces to the same vehicle interior positions. The main objective is to optimize sound package distribution and to prioritize which areas should have the sound package reinforced in order to improve Tire and Engine noise reduction.

Several shortcomings of mechanical door checks are overcome using a magnetorheological damper. Because the damper is electrically actuated, it can check in any desired position. The logical decision to activate or release the door check can be made either by passive circuitry based on input signals from switches attached to door handles or under microprocessor control, in which case the decision can take into account a variety of unconventional input factors, including the magnitude of the force applied to the door, the rate of change of the applied force, and the angle of door opening. With the addition of an appropriate proximity sensor, the controllable damper can prevent the door from inadvertently hitting a nearby obstacle. Details of the damper mechanism are described, and several implemented control strategies, both passive and microprocessor based, are discussed.

A new experimental methodology has been developed to quantify spindle loads of a vehicle under actual operational conditions. The methodology applies an indirect six degree-of-freedom (6 DOF) frequency response function (FRF) measurement technique to obtain three translation/force and three rotation/moment FRFs of the suspension system of the vehicle. The Inverse Frequency Response Function (IFRF) method estimates the spindle loads under operational conditions. The feasibility and applicability of the developed methodology for vehicle road NVH applications was experimentally demonstrated. The results show that the methodology provides accurate spindle load estimation over a broad frequency range. This methodology can be used for benchmarking and target setting of spindle loads to achieve desired road NVH performance as well as for diagnosing root causes in problem solving applications.

The objective of this project was to develop a methodology for the diagnosis of vibrations of the vehicle's steering wheel. This paper will describe an attempt at developing a systematic approach for describing the vibrations felt, what the sources might be, and how various steering system parameters might affect the vibrations.

The paper presents the systematic approaches toward robust stability analysis of H2/H∞ controlled active suspension systems. The computational algorithms for the structured singular value μ are the main features of the work with an emphasis on quantifying the effects of uncertainty of the systems. The representation of vehicle parameter uncertainties is given in detail. The robustness test is subsequently done based on a quarter vehicle model. The results have showed that the H∞ controller is the best one on both robust stability and robust performance.

Recent investigations by others have indicated that the dynamic response of automotive brake rotors in the squeal frequency range involves the classic flexural modes as well as in-plane motion. While the latter set creates primarily in-plane displacements, there is coupling to transverse displacements that might produce vibrational instabilities. This question is investigated here by analyzing a modal model that includes two modes of the rotor and two modes of the pad and caliper assembly. Coupling between in-plane and transverse displacements is explicitly controlled. Results from this model indicate that the coupling does create vibrational instabilities. The instabilities, whose frequencies are in the squeal range, are characterized by power flow through the transverse motion of the rotor.

A stochastic simulation based on the Monte-Carlo method was developed to re-target gap bulk density (GBD) in ceramic catalytic converters. The combined effect of manufacturing tolerances, shell spring back and thermal expansion was analyzed by this model. Shell spring back during the canning process was calculated using Finite Element Analysis (FEA). Thermal shell expansion was obtained using can deformation data from the Key-Life Test (KLT). An example of optimized GBD that provides a robust and manufacturable design is also presented.

Sliding door designs are applied to rear side doors on vans and other large vehicles with a trend towards dual sliding doors with power operation. It is beneficial for the vehicle user to reduce the weight of and space occupied by these doors. Alcoa, in conjunction with Ford, has developed a multi-product, multi-material-based solution, which significantly reduces the cost of an aluminum sliding door and provides both consumer delight and stamping-assembly plant benefits. The design was successfully demonstrated through a concept readiness/technology demonstration program.